Abstract
Aim. To determine relation between localization, grade of invasion and differentiation in rectal tumor and tumor regression grade after neoadjuvant chemoradiation therapy.
Methods. 88 patients with local advanced rectal cancer (Т2-4N0-2М0) were analyzed: 46 females and 42 males. The average age was 52.4±1.4 years. All patients underwent neoadjuvant chemoradiotherapy. In all groups regardless of tumor localization patients with stage T3 and moderate differentiation grade predominated.
Results. Complete pathological tumor response of grade 4 (TRG4) was revealed in 13 (14.7%) patients, grade 3 (TRG3) in 34 (38.6%) patients, low treatment effect (tumor response grade 2, TRG2) was registered in 26 (29.5%) patients, and lack of treatment effect (grade 1, TRG1) in 15 (17.2%) patients. Analysis of the data from patients with complete or nearly complete tumor regression (grade 3 and 4) demonstrated that such effect of neoadjuvant treatment was most often observed in patients with tumor localized in rectal lower ampulla (58.6%). Among patients with moderately differentiated adenocarcinomas, patients with tumor response of grade 3 and 4 predominated: 28 (56%) patients. According to invasion grade, in all groups patients with therapeutic response grade 3 and 4 prevailed, but most prominently - in groups of patients with stage T4a and T4b - 58.9%.
Conclusion. The closer to anus tumor is located, the more significant effect neoadjuvant therapy has; moderate tumor differentiation grade can be considered as a relative predictive factor of tumor regression on preoperative chemoradiation therapy.